我一直在尝试从此Tutorial修改代码，以便在子弹打击敌人后，player.png图像显示在位置x = 60和y = 48。但是图像确实不保持固定，它只是出现而消失。我不知道代码中错误或丢失的元素的确切位置，但我怀疑原因之一是for函数中draw_reaction循环的部分误用。
我的player.png图像
我的MWE代码：
import pygame
import random
# Define some colors
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
BLUE = (0, 0, 255)
# --- Classes
class Block(pygame.sprite.Sprite):
""" This class represents the block. """
def __init__(self, color):
# Call the parent class (Sprite) constructor
super().__init__()
self.image = pygame.Surface([20, 15])
self.image.fill(color)
self.rect = self.image.get_rect()
class Player(pygame.sprite.Sprite):
""" This class represents the Player. """
def __init__(self):
""" Set up the player on creation. """
# Call the parent class (Sprite) constructor
super().__init__()
self.image = pygame.Surface([20, 20])
self.image.fill(RED)
self.rect = self.image.get_rect()
def update(self):
""" Update the player's position. """
# Get the current mouse position. This returns the position
# as a list of two numbers.
pos = pygame.mouse.get_pos()
# Set the player x position to the mouse x position
self.rect.x = pos[0]
class Bullet(pygame.sprite.Sprite):
""" This class represents the bullet . """
def __init__(self):
# Call the parent class (Sprite) constructor
super().__init__()
self.image = pygame.Surface([4, 10])
self.image.fill(BLACK)
self.rect = self.image.get_rect()
def update(self):
""" Move the bullet. """
self.rect.y -= 3
# --- Create the window
# Initialize Pygame
pygame.init()
# Set the height and width of the screen
screen_width = 700
screen_height = 400
screen = pygame.display.set_mode([screen_width, screen_height])
# --- Sprite lists
# This is a list of every sprite. All blocks and the player block as well.
all_sprites_list = pygame.sprite.Group()
# List of each block in the game
block_list = pygame.sprite.Group()
# List of each bullet
bullet_list = pygame.sprite.Group()
# --- Create the sprites
for i in range(0,1,2):
# This represents a block
block = Block(BLUE)
# Set a random location for the block
block.rect.x = random.randrange(screen_width)
block.rect.y = random.randrange(350)
# Add the block to the list of objects
block_list.add(block)
all_sprites_list.add(block)
# Create a red player block
player = Player()
all_sprites_list.add(player)
player_image = pygame.image.load("player.png").convert()
# Loop until the user clicks the close button.
done = False
# Used to manage how fast the screen updates
clock = pygame.time.Clock()
score = 0
player.rect.y = 370
# -------- Main Program Loop -----------
while not done:
# --- Event Processing
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
elif event.type == pygame.MOUSEBUTTONDOWN:
# Fire a bullet if the user clicks the mouse button
bullet = Bullet()
# Set the bullet so it is where the player is
bullet.rect.x = player.rect.x
bullet.rect.y = player.rect.y
# Add the bullet to the lists
all_sprites_list.add(bullet)
bullet_list.add(bullet)
# --- Game logic
# Call the update() method on all the sprites
# Calculate mechanics for each bullet
for bullet in bullet_list:
# See if it hit a block
block_hit_list = pygame.sprite.spritecollide(bullet, block_list, True)
# For each block hit, remove the bullet and add to the score
for block in block_hit_list:
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
score += 1
print(score)
# Remove the bullet if it flies up off the screen
if bullet.rect.y < -10:
bullet_list.remove(bullet)
all_sprites_list.remove(bullet)
def draw_reaction():
for bullet in bullet_list:
block_hit_list = pygame.sprite.spritecollide(bullet, block_list, True)
for block in block_hit_list:
screen.blit(player_image, [60, 48])
all_sprites_list.update()
# --- Draw a frame
# Clear the screen
screen.fill(WHITE)
draw_reaction()
# Draw all the spites
all_sprites_list.draw(screen)
# Go ahead and update the screen with what we've drawn.
pygame.display.flip()
# --- Limit to 20 frames per second
clock.tick(60)
pygame.quit()
编辑更新：每次游戏重新开始时，游戏中只有一个敌人出现在随机位置。
编辑更新2：我知道，在大多数游戏中，碰撞后敌人会从屏幕上移开。这也发生在我的代码中。但是出于我的特殊需要，因此，在与敌人的子弹碰撞后，图像（player.png）会保持不变。
问题是由draw_reaction()函数引起的，它仅在子弹与块碰撞的绝对时间内绘制player_image。因此它只显示一帧图像（每秒60分之一秒），但是在下一个循环中不再发生碰撞（移走了项目符号），因此从不绘制图像。
有许多解决方法，但是我不确定显示此位图的目的，所以也许它们没有应有的帮助。
最简单的解决方法是将播放器图像转换为精灵图像，并在触发子弹击中时将其简单地添加到现有的all_sprites_list中，然后在一段时间后将其删除（或如何工作）。
class PlayerShip( pygame.sprite.Sprite ):
def __init__(self):
super().__init__()
self.image = pygame.image.load( "player.png" ) #.convert()
self.rect = self.image.get_rect()
self.rect.topleft = ( 60, 48 )
随后再说：
player_sprite = PlayerShip()
和
def draw_reaction():
for bullet in bullet_list:
block_hit_list = pygame.sprite.spritecollide(bullet, block_list, True)
for block in block_hit_list:
# TODO: ensure it's not showing already
all_sprites_list.add( player_sprite ) # add the player sprite
break # only add once
编辑：基于评论更新的代码片段